A 6 year-old girl with brain atrophy

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A 6 YEAR-OLD GIRL WITH BRAIN ATROPHY

Teaching NeuroImages

Neurology

Resident and Fellow Section

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Vignette

• A 6 year-old girl with an unknown neurodegenerative disorder was admitted for a cluster of seizures.

• MRI of the brain showed diffuse atrophy and bilateral and symmetrical T2/FLAIR hyperintense signal

intensity in the thalami

• This was considered suggestive of metabolic derangement, medications, viral infection, or secondary to her recent seizures.

• Given her history of progressive impairments, a

mitochondrial or metabolic condition was suspected.

Helbig and Adang, 2007

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Imaging

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A 6 year-old girl with brain atrophy

• At the age of 12 years, the patient was found to have a de novo KCNT1 pathogenic variant. KCNT1, a gene encoding for a

potassium channel subunit, is the cause of a broad range of epileptic encephalopathies, most notably Malignant Migrating Focal Seizures of Infancy ¹.

• Genetic epilepsies may present with clinical features suggesting neurodegenerative or neurometabolic disorders or

leukodystrophies ². Albeit rare, genetic epilepsies due to de novo mutations are significantly more common by probably more than an order of magnitude and atypical presentations of more

common channelopathies may be on the differential for unsolved neurodegenerative disorders with an atypical pattern.